Let me begin by stating that contrary to some recent headlines and sources, “ONWASA water is NOT contaminated”.
So why was this said by some about ONWASA water?
ONWASA recently sent a letter to our customers as required under a new EPA rule, Stage 2 Disinfectant By-Product Rule, which took effect in May 0f 2012. Under this new rule previous testing results reporting higher levels of Trihalomethanes (THM) in one area of the ONWASA distribution system where the waterline doesn’t experience rapid turnover is now required by the EPA to be reported using the template and wording they provide. The fact is that current test results are typical of those from previous years, and a Notice was not required until now.
Is this required reporting a bad thing?
Not at all. Keeping our public informed is a big part of being good stewards of the public trust. ONWASA reports to all water customers THM and all other testing results for the entire water system over the entire year on an annual basis. The report, entitled Consumer Confidence Report, is direct mailed to all customers and contains information explaining what the test results are and what they mean, as well as information explaining what concentrations of tested items could cause concern. The Consumer Confidence Report is also posted on ONWASA’s website at http://www.onwasa.com/143/Reports .
So if that is the case, then why the scary language in the Notice that was sent?
All language in the Notice was dictated to ONWASA by the EPA. It is possible the new rule and language requirement may be indicative of overall EPA reporting changes and requirements.
But what if the new rule change and reporting requirements are because we have just now found there is a danger we did not earlier understand?
The science on the subject of THM consumption has not changed. To understand the possible health effects for many regulated constituents including THMs, a person would have to drink 2 liters of water every day at the MCL level for a lifetime to have a one-in-a-million chance of having any of the described health effects. The fact is that a human being of average size would have to ingest more water than humanly possible for years…maybe even decades…to have roughly the same chance as winning the lottery of it causing ill effects. This is definitely not meant to diminish the value of testing and reporting, but rather is meant to give perspective. Scientific studies also attribute most of the same risks to the grilling of our food on charcoal grills, but again these risks are also almost infinitesimal.
What exactly are THM’s?
Just as charcoal is a by-product of the grilling process, THM’s are a by-product formed when naturally occurring organic compounds in water react with disinfectants.
Even though the THM’s may not be a problem, what if I would still feel better if they were not there?
There are two ways to accomplish the elimination of THM’s in the water system. The first is to not allow time for the by-product to form. To this end ONWASA has installed automatic flushing devices that flush water from the line to not allow time for formation of the THM. The second is to remove the compounds required to form the by-product. Disinfection is necessary to prevent bacterial growth from occurring in water lines as it travels from the source to your home. The State mandates chlorine (disinfectant) levels be maintained between 4.00 mg/l to 0.20 mg/l and ONWASA’s average for the system is 0.80 mg/l. Since disinfectant is desirable and a mandated requirement, ONWASA obtained funding and is currently constructing a Reverse Osmosis process at the Dixon Water Treatment facility. This will remove organic compounds before they enter the system and is scheduled for completion November 2014.
ONWASA performs an almost unbelievable amount of testing to our water to ensure its quality before allowing it to be consumed. Because of the makeup of ground water in the Eastern part of North Carolina we are very conservative and err on the side of caution with testing, boil water advisories and construction of better treatment processes to assure the quality of the water being provided for consumption.
I hope this information is helpful. If you have more questions, or if you are just curious about how the whole water production process works, please let us know. ONWASA’s highly trained and dedicated staff will be very happy to show you what they do.
Billy Joe Farmer
Executive Director, ONWASA
